Research on porous media is of major importance to many fields varying from catalysis to Earth science. Characterizing such media in 3D is expected to provide information on surface and volume rendering, which is required for understanding fluid transport. In the present study, electron tomography performed in the FIB-SEM (Focused Ion Beam – Scanning Electron Microscope) [1] is applied to a highly porous Diatomaceous Earth material. Representative volumes (Figure 1) have been obtained and treated in Fiji and Avizo software, the pore volume and pore connections are studied and quantified to generate the pore network [2-5]. Next, the data is used for fluid simulation through Computational Fluid Dynamics (CFD) methods, in order to study and analyze flow and diffusion properties in the obtained pore network (Figure 2). The geometry of pores is also evaluated to study how it influences transport properties in the sample. Furthermore, the effects of image correction and segmentation on the simulation are also examined.

[1] L. Holzer et al, Journal of Microscopy, 216 (2004), 84–95.

[2] P.S. Jørgensen et al, Utramicroscopy, 110 (2010), 216-228.

[3] T. Prill et al, Journal of Microscopy, 250 (2013), 77–87.

[4] M. Salzer et al, Journal of Microscopy, 257 (2015), 23–30.

[5] K.R. Mangipudi et al, Utramicroscopy, 163(2016), 38-47.

Figures:

Figure 1: a) An image of the cross section from a prepared region of interest for the ‘Slice & View’ tomographic procedure; b) segmented pore phase in one obtained volume of nearly 2500 µm3.

Figure 2: Flow simulation result in one XZ cut plane through a target volume of 200*200*200 voxels (voxel size is 12.5*12.5*20 nm3) extracted from the total volume in Figure 1b. Vertical velocity component contours are shown with flow moving upwards.